Separate arch origin of the left external carotid artery with common trunk giving rise to the left internal carotid artery and left subclavian artery.

We present a case of a 3-year-old boy with tetralogy of Fallot having the direct origin of the left external carotid artery from the aorta with a common trunk giving rise to the left internal carotid artery and left subclavian artery, in a right-sided aortic arch. We also highlight the potential implications in management.

Angiographic Characterization of the External Carotid Artery: Special Attention to Variations in Branching Patterns.

Knowledge of branching patterns of external carotid artery (ECA) is essential for planning and execution of head and neck surgeries. Digital subtraction angiography (DSA) images of 532 ECAs from 302 consecutive patients were retrospectively evaluated. We classify the branch variants of ECA into three types, simply based on the number of branches arising close together. Type A, Type B, and Type C variants are defined as two, three, and four or more branches of ECAs arising at a common point from the proximal ECA, respectively. In this classification, the distal ECA was counted as one branch. Of 532 ECAs, Type A was found in 344 ECAs (64.6%) of 237 patients (78.5%), Type B in 134 ECAs (25.2%) of 110 patients (36.4%), and Type C in 54 ECAs (10.2%) of 49 patients (16.2%). The distance from the common carotid artery (CCA) bifurcation to the first branch of ECA with Type C was 14.7 ± 6.6 mm; its distance is shorter compared with Type A (21.8 ± 15.6 mm) and Type B (20.6 ± 8.9 mm) (P < 0.05). The position of CCA bifurcation with Type C was detected at the third-fourth junction cervical vertebral level or higher in 52 of 54 ECAs (96.3%), significantly higher than those of the other types (P < 0.05). In conclusion, Type C ECA has aggregated vessels with short distance from CCA and high position of CCA bifurcation. Type C ECA is not uncommon; thus, special consideration should be paid to avoid complications during surgeries.

Overexpression of Angiopoietin-1 Potentiates Endothelial Progenitor Cells for the Treatment of Aneurysm.

BACKGROUND: To investigate whether angiopoietin-1 (Ang-1) could regulate the endothelial progenitor cells (EPCs) survival and the effect of accelerating intra-aneurysmal organization and occlusion of the aneurysm neck. METHODS: EPCs were isolated from Wistar rats. EPCs were cultured and transfected with lentivirus-Ang-1-endothelial progenitor cells (Ang-1-EPCs) and lentivirus-NC-endothelial progenitor cells (NC-EPCs). The effects of Ang-1 on viability and functioning of EPCs were explored via tube formation, migration, and MTT (3-[4,5-dimethylthiazolyl-2]-2,5-diphenyltetrazolium bromide) assays. Eighteen Wistar rats were randomly allocated into 3 groups. Eighteen bare coils were inserted into the ligated external carotid artery (ECA) sacs of rats. The ECA sacs were removed 2 weeks after the coils were implanted and examined by histology assay. RESULTS: Ang-1 significantly promoted EPCs tube formation, migration, and proliferation ability in vitro. Histology analyses revealed that the organized areas in the ECA sacs in the Ang-1-EPCs group are higher than NC-EPCs group and control group at 2 weeks. Immunofluorescence revealed that organized tissues were characterized by an accumulation of cells positive for α-smooth muscle actin-positive cells in aneurysm sacs. CONCLUSIONS: Overexpression of Ang-1 enhanced the tube formation, migration, and proliferation ability of EPCs. Ang-1 gene-modified EPCs accelerated organization within the aneurysms and occlusion of aneurysm neck. Transplantation of Ang-1-transfected EPCs may be a new method for the treatment of aneurysm.

A Rare Cause of Juvenile Stroke: Extracranial Carotid Artery Aneurysm with Venous Complete Reconstruction of the Carotid Bifurcation.

Extracranial carotid artery aneurysms (ECAA) are a rare cause of embolic stroke. The underlying etiology is variable, with atherosclerosis being the most common entity in older subjects. Several treatments have been developed over the last 20 years, but the preferred method remains unknown. Notwithstanding the widespread use of endovascular techniques, surgical reconstruction by means of a bifurcated venous bypass graft should be applied in younger patients. In this way, it is possible to avoid major concerns about the development of long-term intrastent restenosis, and also to spare the external carotid artery which represents the main branch for the ipsilateral cerebral and facial perfusion. We propose ECAA resection and interposition of the inverted great saphenous vein to both the internal and external carotid artery by means the use of a tributary, i.e., the Giacomini vein.

Effect of Cervical Siphon of External and Internal Carotid Arteries.

Variant courses, configuration, and branching pattern of the external and internal carotid arteries, especially when curved in S-shape, are important for hemodynamic changes and clinical implications. Therefore, the aim of the study is to report abnormal cervical siphons observed in external and internal carotid arteries to explore clinical significance by review of literature and hemodynamic changes theoretically.The right common carotid artery bifurcated into external and internal carotid arteries at the level of the upper border of thyroid cartilage in a 70-year-old female cadaver. After bifurcation, the external carotid artery underwent severe tortuosity coursing through 5 bends at points A, B, C, D, and E from its origin to termination and 2 bends at A' and B' in internal carotid artery in the cervical region. The angles between inflow and out flow of the blood at the bends were measured and the change in velocity at each bend was computed for both arteries. Hemodynamic changes were calculated, compared and relevant clinical complications were theoretically correlated.The angles of 20°, 30°, 51°, 52°, 60°, and 28°, 48° were formed by 5 bends of external and 2 bends of internal carotid arteries, respectively. The curved courses of these arteries caused reduction in velocity/stasis, turbulence, and low shear stress. Such kinks might cause stroke, ischemia and mistaken for tumors and abscess in imagery leading to or otherwise producing iatrogenic repercussions. This study will be useful for anatomists, clinicians, and radiologists.

[Simultaneous operation in a patient with stenosis of the extracranial portion and an intracranial aneurysm of the internal carotid artery]. / Simul'tannaia operatsiia u bol'nogo so stenozom ékstrakranial'nogo otdela i intrakranial'noi anevrizmoi vnutrennei sonnoi arterii.

Presented herein is a clinical case report concerning surgical treatment of a patient with a rare combination of two pathologies, i. e., a haemodynamically significant stenosis of the extracranial portion and a sacciform aneurysm of the communicative portion of the right internal carotid artery on the background of multifocal atherosclerosis. The patient underwent a simultaneous operation consisting in clipping of the sacciform arterial aneurysm of the communicative portion of the right internal carotid artery and carotid endarterectomy on the right. The chosen surgical policy ensured effective prevention of the development of ischaemic stroke and rupture of the arterial aneurysm, whose risks would have been high in staged treatment and sequentially performing two operations.

Aspirin and Clopidogrel Inhibit Aneurysm Healing after HydroCoil Implantation in External Carotid Artery Aneurysm Model.

PURPOSE: To understand whether the use of antiplatelet agents leads to less intra-aneurismal tissue formation following coil implantation in a rat end-pouch external carotid artery (ECA) aneurysm model. METHODS: End-pouch ECA aneurysms were created in adult rats and were then embedded with either platinum or HydroCoils. Rats were treated either with aspirin, clopidogrel, aspirin + clopidogrel, or saline for 2 weeks after coil implantation. At 2 weeks after coil implantation, rats were sacrificed and the aneurysm pouch was removed for histological and immunohistochemical analysis. A blinded single observer calculated the percentage of the organized area and the residual length of elastic lamina within the aneurysm. Student's t-test was used to compare data from image analysis between the different groups. RESULTS: Within the platinum group, the organized tissue area was not affected by antiplatelet administration (aspirin versus saline, P = .83; clopidogrel versus saline, P = .46; aspirin + clopidogrel versus saline, P = .54). For the HydroCoil group, the organized tissue area was significantly reduced (aspirin versus saline, P = .02; clopidogrel versus saline, P = .04; aspirin + clopidogrel versus saline, P = .02) in rats treated with antiplatelet agents; however, no difference (aspirin versus clopidogrel, P = .8; aspirin versus aspirin + clopidogrel, P = .3; clopidogrel versus aspirin + clopidogrel, P = .5) was found among type or combination of antiplatelets administered. HydroCoil-treated aneurysms had a similar number of macrophages compared to the platinum group (P = .3819); however, the HydroCoil group had significant suppression of macrophages in the groups treated with combined antiplatelets (P = .02). CONCLUSION: Following HydroCoil implantation, the area of organized tissue is diminished significantly in a rat end-pouch ECA aneurysm model treated with antiplatelets.

Delayed inhaled carbon monoxide mediates the regression of established neointimal lesions.

OBJECTIVE: Intimal hyperplasia (IH) contributes to the failure of vascular interventions. While many investigational therapies inhibit the development of IH in animal models, few of these potential therapies can reverse established lesions. Inhaled carbon monoxide (CO) dramatically inhibits IH in both rats and pigs when given perioperatively. It also prevented the development of pulmonary arterial hypertension in rodents. Interestingly, CO could reverse pulmonary artery structural changes and right heart hemodynamic changes when administered after the establishment of pulmonary hypertension. Thus, we hypothesize that inhaled CO may mediate the regression of established neointimal lesions. METHODS: Rats underwent carotid artery balloon angioplasty injury. Carotid arteries were collected at 2 and 4 weeks after injury for morphometric analysis of the neointima. Another group was treated with inhaled CO (250 parts per million) for 1 hour daily from week 2 until week 4. Additional rats were sacrificed 3 days after initiating CO treatment, and the carotid arteries were examined for apoptosis by terminal deoxynucleotidyl transferase dUTP nick end-labeling, proliferation by Ki67 staining, and autophagy by microtubule-associated protein light chain 3 I/II staining. RESULTS: At 2 weeks following injury, sizable neointimal lesions had developed (intimal/media = 0.92 ± 0.22). By 4 weeks, lesion size remained stable (0.80 ± 0.09). Delayed inhaled CO treatment greatly reduced neointimal lesion size vs the 2- and 4-week control mice (0.38 ± 0.05; P < .05). Arteries from the CO-treated rats exhibited significantly reduced apoptosis compared with control vessels (3.18% ± 1.94% vs 16.26% ± 5.91%; P = .036). Proliferation was also dramatically reduced in the CO-treated animals (2.98 ± 1.55 vs 10.37 ± 2.80; P = .036). No difference in autophagy between control and CO-treated rats was detected. CONCLUSIONS: Delayed administration of inhaled CO reduced established neointimal lesion size. This effect was mediated by the antiproliferative effect of CO on medial and intimal smooth muscle cells without increases in arterial wall apoptosis or autophagy. Future studies will examine additional time points to determine if there is temporal variation in the rates of apoptosis and autophagy.

Intracranial versus Extracranial Symptomatic Carotid Atherosclerosis in Chinese Patients: Risk Factors, Stroke Mechanisms, and Long-Term Prognosis.

OBJECTIVES: This study aims to investigate the clinical-radiological features and stroke mechanisms of symptomatic intracranial internal carotid artery (IICA) atherosclerosis and prognoses of patients with IICA atherosclosis, and compare these data with those from patients with symptomatic extranial carotid artery (EICA) atherosclerosis. METHODS: We prospectively recruited 155 patients with symptomatic IICA or EICA atherosclerosis (stenosis ≥50% or occlusion) from 1968 Chinese patients with a first-ever ischemic stroke or transient ischemic attack. The patients were followed up for stroke recurrence, cardiovascular events, and death. RESULTS: There were 80 and 75 patients in the IICA and EICA groups, respectively. Multivariate logistic regression analyses showed that the patients in the IICA group were associated with hypertension (odds ratio [OR], 5.980; 95% confidence interval [CI], 1.790-19.976) and asymptomatic intracranial atherosclerosis (OR, 2.564; 95% CI, 1.222-5.377), while the patients in the EICA group were associated with smoking (OR, 2.397; 95% CI, 1.150-4.998) and contralateral EICA disease (OR, 4.742; 95% CI, 1.455-15.455). Hemodynamic stroke alone was more common in the IICA group; artery-to-artery embolism was identified more often in the EICA group (P <.05). The cumulative incidences of ipsilateral stroke recurrence, stroke recurrence and cardiovascular events, and death at 5 years were 43.5%, 52.4%, and 27.3%, respectively, in the patients of the IICA group, which did not differ from those of the EICA group. CONCLUSIONS: IICA atherosclerosis as well as EICA atherosclerosis is an important cause of stroke in Chinese patients. Patients with symptomatic IICA atherosclerosis had unique clinical-radiological features and stroke mechanisms compared with those with symptomatic EICA atherosclerosis; their long-term prognosis was poor.

Presence of external carotid artery plaque independently predicts mortality in patients without internal carotid artery atherosclerosis.

BACKGROUND: The presence of plaque in the external carotid artery (ECA) detected on carotid duplex ultrasound (CDU) is of unknown clinical significance and may not be reported in routine clinical practice. We hypothesize that ECA plaque in the absence of plaque in the other cervical vessels is a risk factor for increased all-cause mortality. OBJECTIVES: To determine the significance of ECA plaque on all-cause mortality in the absence of internal carotid artery (ICA) or common carotid artery (CCA) plaque. METHODS: We queried the Non-Invasive Vascular Laboratory database for all CDUs performed between 1 January 2005 and 31 December 2005. All images were reviewed for the presence of plaque. Studies were included if plaque was absent in both the CCA and the ICA. Chart review was performed to obtain demographic and clinical information. All-cause mortality was determined using the Social Security Death Index. RESULTS: A total of 500 patient studies met the inclusion criteria; 64 patients (12.8%) had plaque in one or both ECAs. There was no significant difference in age (mean 58.1 ± 14.8 years), race (82.5% white), or sex (64.4% male) between those with and without ECA plaque. There was a significant difference in all-cause mortality between patients with and without isolated ECA plaque after adjustment for age, sex, low-density lipoprotein cholesterol, smoking, hypertension, body mass index, and surgery within 30 days of CDU (adjusted hazard ratio 2.60, 95% CI 1.46-4.66, p<0.001). CONCLUSIONS: The presence of plaque isolated to the ECA is an independent predictor of all-cause mortality and may impart important prognostic information for patients referred for CDU.

Different risk factors between intracranial and extracranial atherosclerotic stenosis in Asian population: a systematic review and meta-analysis.

Sex, hypertension, diabetes, dyslipidemia, smoking, age and metabolic syndrome (MetS) are major vascular risk factors for intracranial or extracranial atherosclerotic stenosis (ICAS or ECAS) in Asian population. Here, we performed a meta-analysis to evaluate the different influence of these factors on ICAS compared to ECAS in Asian population, by searching PUBMED, EMBASE and Web of Science databases. Sensitivity analysis was performed by repeating the fixed or random effects model meta-analysis with removing each study individually. All statistical analysis was conducted with Stata 11.0. Finally, 15 studies including 3787 patients were identified, 2661 patients in ICAS group and 1126 patients in ECAS group, respectively. Our results showed that female or the patients with MetS were more likely to suffer from ICAS than ECAS, which pooled ORs of ICAS versus ECAS were 2.16 (95% CI: 1.65-2.83, p < 0.0001) and 1.68 (95% CI: 1.32-2.12, p < 0.0001), respectively. Meanwhile, the smoker or the patients with dyslipidemia were more likely to suffer from ECAS than ICAS, which pooled ORs of ICAS versus ECAS were 0.71 (95% CI: 0.61-0.84, p < 0.0001) and 0.75 (95% CI: 0.63-0.90, p = 0.002), respectively. However, age, hypertension and diabetes had not different influence on the location of atherosclerotic stenosis, and the pooled MD and ORs were -0.69 (95% CI: -1.52-0.15, p = 0.11), 1.08 (95% CI: 0.92-1.27, p = 0.34) and 1.02 (95% CI: 0.88-1.19, p = 0.76), respectively. Our results suggested that female sex and MetS were more associated with ICAS, while smoking and dyslipidemia were more associated with ECAS. There was no significant difference between ICAS and ECAS in terms of age, hypertension and diabetes.

[Structural and functional changes of external and intracranial arteries in elderly patients of different ethnic groups with ischemic heart disease].

The present article discusses the problem of structural and functional changes in extra-and intracranial arteries in elderly patients with ischemic heart disease (CHD) belonging to different ethnic groups before the upcoming coronary arteriography research and planned operative intervention. We examined 120 elderly patients with ischemic heart disease, including 50 patients of Korean nationality and 70 patients of Slavic ethnicity. Average values of IMT of the right and left CCA patients of South Asian group were significantly lower than those of Slavic ethnicity. Elderly patients with CHD the violation of cerebral circulation were due to atherosclerotic lesions of the extracranial vessels and local hemodynamic disturbances in their area of pathological tortuosity. Korean ethnicity elderly patients with CHD were observed more pronounced signs of stenosis and deformation of the main arteries of the neck, as well as lower collateral reserve of cerebral circulation.

Internal and external carotid artery embolism following facial injection of autologous fat.

Autologous fat injection is a common aesthetic procedure for soft-tissue augmentation of the face. Although this procedure is generally regarded as safe, several patients have experienced acute visual loss or cerebral infarction after these injections. We describe a case of internal and external carotid artery fat embolism that occurred following injection of autologous fat into the face. It appeared that the injected fat entered a branch of the left external carotid artery and that the embolus likely migrated into the left internal carotid artery and distally into the left ophthalmic artery, left anterior artery, and middle cerebral artery. LEVEL OF EVIDENCE 5:

Evaluation of the outcomes of endovascular management for patients with head and neck cancers and associated carotid blowout syndrome of the external carotid artery.

AIM: To evaluate factors related to the technical and haemostatic outcomes of endovascular management in patients with head and neck cancers (HNC) associated with carotid blowout syndrome (CBS) of the external carotid artery (ECA). MATERIALS AND METHODS: Between 2002 and 2011, 34 patients with HNC with CBS involving branches of the ECA underwent endovascular therapy. Treatment included embolization with microparticles, microcoils, or acrylic adhesives. Fisher's exact test was used to examine demographic features, clinical and angiographic severities, and clinical and imaging findings as predictors of endovascular management outcomes. RESULTS: Technical success and immediate haemostasis were achieved in all patients. Technical complications were encountered in one patient (2.9%). Rebleeding occurred in nine patients (26.5%). Angiographic vascular disruption grading from slight (1) to severe (4) revealed that the 18 patients with acute CBS had scores of 2 (2/18, 11.1%), 3 (3/18, 16.7%), and 4 (13/18, 72.2%). The 16 patients with impending and threatened CBS had scores of 1 (1/16, 6.25%), 2 (5/16, 31.25%), and 3 (10/16, 62.5%; p = 0.0003). For the 25 patients who underwent preprocedural computed tomography (CT)/magnetic resonance imaging (MRI) examinations within 3 months of treatment, the agreement between clinical and imaging findings reached the sensitivity, specificity, and kappa values for recurrent tumours (1, 0.7143, 0.7826), soft-tissue defect (0.9091, 0.3333, 0.2424), and sinus tract/fistula (0.4737, 0, 0.4286). CONCLUSION: Endovascular management for patients with CBS of the ECA had high technical success and safety but was associated with high rebleeding rates. We suggest applying aggressive post-procedural follow-up and using preprocedural CT/MRI to enhance the periprocedural diagnosis.

An improved elastase-based method to create a saccular aneurysm rabbit model.

PURPOSE: To find a safe, effective, and simple method to create a rabbit aneurysm model. METHODS: Twelve adult New Zealand rabbits were divided into two groups: experimental (n = 9) and control (n = 3). The origin of the right external carotid artery was occluded with a temporary aneurysm clip, after which the right external carotid artery was ligated distally. The resulting stump was infused with elastase (experimental group) or saline (control group) for 20 minutes, and the clip was removed. The animals were studied angiographically and sacrificed 3 weeks after the procedure to harvest the aneurysms for histological analysis. RESULTS: All nine rabbits in the experimental group successfully developed aneurysm after 3 weeks. Aneurysms had an average height of 5.2 ± 1.1 mm and width of 3.5 ± 0.8 mm. Histological analysis showed that the tunica media of the aneurysmal wall was barely identifiable. None of the three rabbits in the control group developed an aneurysm, and instead had achieved closure of the right external carotid artery stump. CONCLUSIONS: We have established an effective and a simple elastase-based method to create a rabbit aneurysm model. The procedure is easy to perform and does not require an interventional technique and or ligation of the internal carotid artery, which would otherwise reduce the blood supply to the brain.

Preoperative Embolization of Primary Juvenile Nasopharyngeal Angiofibroma: Is Embolization of Internal Carotid Artery Branches Necessary?

PURPOSE: To determine the effects of blood supply from internal carotid artery (ICA) on the surgical outcomes of primary juvenile nasopharyngeal angiofibroma (JNA) after transarterial embolization (TAE). METHODS: A retrospective analysis was performed on primary JNA patients who underwent TAE and endoscopic resection in our hospital between December 2020 and June 2022. The angiography images of these patients were reviewed, and then they were divided into ICA + external carotid artery (ECA) feeding group and ECA feeding group according to whether the ICA branches were part of the feeding arteries. Tumors in ICA + ECA feeding group were fed by both ICA and ECA branches, while tumors in ECA feeding group were fed by ECA branches alone. All patients underwent tumor resection immediately after ECA feeding branches embolization. None of the patients underwent ICA feeding branches embolization. Data on demographics, tumor characteristics, blood loss, adverse events, residual and recurrence were collected, and case-control analysis was performed for the two groups. Differences in characteristics between the groups were tested using Fisher's exact and Wilcoxon tests. RESULTS: Eighteen patients were included in this study: nine in ICA + ECA feeding group and nine in ECA feeding group. The median blood loss was 700 mL (IQR 550-1000 mL) in ICA + ECA feeding group versus 300 mL (IQR 200-1000 mL) in ECA feeding group, with no significant statistical difference (P = 0.306). Residual tumor was found in one patient (11.1%) in both groups. Recurrence was not observed in any patient. There were no adverse events from embolization and resection in either group. CONCLUSION: The results of this small series suggest that the presence of blood supply from ICA branches in primary JNA has no significant effect on intraoperative blood loss, adverse event, residual and postoperative recurrence. Therefore, we do not recommend routine preoperative embolization of ICA branches. LEVEL OF EVIDENCE: Level 4, Case-control.

Association between Carotid Bifurcation Angle and Vulnerable Plaque Volume Using Black Blood Magnetic Resonance Imaging.

The morphology of the internal carotid artery (ICA) bifurcation is increasingly being recognized as the cause of atherosclerosis and vulnerable plaque leading to cerebral infarction. In this study, we investigated the relationship between carotid bifurcation angle and carotid plaque volume evaluated using black blood magnetic resonance imaging (BB-MRI). Among the 90 patients who underwent revascularization for atherosclerotic symptomatic carotid stenosis between April 2016 and October 2022 using BB-MRI, carotid plaque was evaluated in 57 patients. Relative overall signal intensity (roSI) was defined as the signal intensity of the plaque on T1-weighted images relative to the signal intensity of the sternocleidomastoid muscle in the same slice as the common carotid bifurcation. Regions showing roSI ≥ 1.0 were defined as plaque, and the plaque volume and relative plaque volume were measured from roSI ≥1.0 to ≥2.0 in 0.1 increments. We calculated the angles between the common carotid artery (CCA) and the ICA and between the CCA and the external carotid artery (ECA) on magnetic resonance angiography. We classified two groups according to carotid bifurcation angles based on the ICA angle: Group A = <35° and Group B = ≥35°. Compared with Group A (n = 42), Group B (n = 15) showed a greater relative plaque volume between roSI ≥ 1.3 and roSI ≥ 1.5. A significant correlation was identified between relative plaque volume with roSI ≥ 1.4 and ICA angle (p = 0.049). Vulnerable plaque was significantly more frequent in the group with an ICA angle of ≥35. Moreover, the ICA angle was significantly greater in patients with a roSI of ≥1.4.

Shear stress-induced activation of Tie2-dependent signaling pathway enhances reendothelialization capacity of early endothelial progenitor cells.

Although endothelial progenitor cells (EPCs) play a pivotal role in the endothelial repair following arterial injury and shear stress has a beneficial effect on EPCs, however, the molecular mechanism underlying the influence of EPCs on the endothelial integrity and the regulation of shear stress on the EPC signaling remained to be studied. Here, we investigated the effects of laminar shear stress on the tyrosine kinase with immunoglobulin and epidermal growth factor homology domain-2 (Tie2)-dependent signaling and its relation to in vivo reendothelialization capacity of human early EPCs. The human early EPCs were treated with shear stress. Shear stress in a dose-dependent manner increased angiopoietin-2 (Ang2)-induced migratory, adhesive and proliferatory activities of EPCs. Transplantation of EPCs treated by shear stress facilitated in vivo reendothelialization in nude mouse model of carotid artery injury. In parallel, the phosphorylation of Tie2 and Akt of EPCs in response to shear stress was significantly enhanced. With treatment of Tie2 knockdown or Akt inhibition, shear stress-induced phosphorylation of Akt and endothelial nitric oxide synthase (eNOS) of EPCs was markedly suppressed. After Tie2/PI3K/Akt/eNOS signaling was blocked, the effects of shear stress on in vitro function and in vivo reendothelialization capacity of EPCs were significantly inhibited. The present findings demonstrate for the first time that Tie2/PI3k/Akt/eNOS signaling pathway is, at least in part, involved in the EPCs-mediated reendothelialization after arterial injury. The upregulation of shear stress-induced Tie2-dependent signaling contributes to enhanced in vivo reendothelialization capacity of human EPCs.

The influence of obesity on the assessment of carotid intima-media thickness.

BACKGROUND: The assessment of carotid intima-media thickness (CIMT) may improve cardiovascular risk prediction. The optimal protocol for CIMT measurement is unclear. CIMT may be measured in the common carotid artery (CCA), carotid bifurcation (CB), and internal carotid artery (ICA), but measurements from CB and ICA are more difficult to obtain. We studied the influence of body mass index (BMI) and atheroma plaques on the capacity to obtain CIMT measurements at different carotid sites. METHODS: Using an automatic system, CIMT was measured in 700 subjects aged 45-75, in the near and far walls of CCA, CB, and ICA bilaterally. The presence of atheroma plaques, BMI and vascular risk factors were recorded. RESULTS: CIMT measurements in CCA were possible in all except one subject. It was not possible to obtain CIMT measurements at CB or ICA in 24.1% of normal weight and 58.8% of obese subjects. The likelihood of obtaining CIMT measurement at all carotid sites decreased as the BMI increased. Atheroma plaques in a carotid segment did not preclude CIMT measurement at this site. CONCLUSIONS: CIMT measurements in distal carotid segments are more challenging in obese subjects. Measuring CIMT at CCA remains feasible in obese subjects and should be the primary endpoint in these subjects. Nevertheless, CB and ICA measurements, when feasible, would improve risk classification.